1. Field of the Invention
The present invention relates to an image comparing apparatus, an image comparing method, a computer readable medium recording a program for image comparison, a photographing apparatus, and a photographing method. More particularly, the present invention relates to an image comparing apparatus, an image comparing method, a computer readable medium recording a program for image comparison, a photographing apparatus, and a photographing method for comparing a particular inspect image having a subject image with a plurality of search images.
2. Description of the Related Art
Conventionally, a method of comparing search images obtained by photographing a subject with an inspect image has been proposed for identifying a subject of the inspect image. According to such a conventional method, if the subject of the inspect image and the search images are captured under the same conditions or environments, the conventional method could produce a good result.
However, in a case where the same subject is photographed but an orientation of the subject or an illumination direction to the subject at a time of capturing the subject image is different between the inspect image and the search images, those images appear different. Thereby, under the consideration, it may be difficult to determine that the subject of the inspect image is the same as that of the search image.
One of the methods for providing a better result than the aforementioned conventional one is, for example, a method in which a plurality of search images is prepared beforehand upon which the subject is photographed under various conditions. Then, each of the search images is compared with the inspect image. However, this method would require cost and time to provide a reasonable result for checking the inspect image. On the other hand, in a case where there are a plurality of subjects to be identified, the inspect image would be falsely identified as similar to the search image regardless that completely different subjects are photographed depending on the orientation of the subject or illumination condition at the time of photographing. Thereby, erroneous judgment could sometimes occur such that the plurality of the subjects is identified as the same subject.